It's an hyperbole. A figure of speech. But I repeat myself.
Let's see the context of the verse...
If you are sincerely interested in context, you need to at least start at verse 9. That's where Paul starts this particular line of thinking, and what he says from that point sets the tone for the verses in question. Better yet, just read chapter 12 in it's entirety. But if not, at least go back to verse 9.
9) Let love be without hypocrisy. Abhor what is evil. Cling to what is good.
10) Be kindly affectionate to one another with brotherly love, in honor giving preference to one another;
11) not lagging in diligence, fervent in spirit, serving the Lord;
12) rejoicing in hope, patient in tribulation, continuing steadfastly in prayer;
13) distributing to the needs of the saints, given to hospitality.
14) Bless those who persecute you; bless and do not curse.
15) Rejoice with those who rejoice, and weep with those who weep.
16) Be of the same mind toward one another. Do not set your mind on high things, but associate with the humble. Do not be wise in your own opinion.
17) Repay no one evil for evil. Have regard for good things in the sight of all men.
18) If it is possible, as much as depends on you, live peaceably with all men.
19) Beloved, do not avenge yourselves, but rather give place to wrath; for it is written, "Vengeance in Mine, I will repay," says the Lord.
20) Therefore
21) Do not be overcome by evil, but overcome evil with good.
Now, if you are determined to believe that the quoted proverb in verse 20 was intended to emphasis God's wrath on your enemy, as mentioned in 19, then a link between 19 and 20 will appear plain as day. But if you were to interpret the proverb as I do, that benevolence can break the cycle of violence, then the link simply isn't there. In other words, the link you point out between 19 and 20 only appears to be there because you interpret the heaping of coals to be an act of hostility. Since you need to prove your interpretation to prove the link, you can't use the link to prove your interpretation; circular reasoning.
So, this is where the other verses come in handy. We can look at the tone of the message Paul is sending. He say be good to each other; be good like this; be good like that. Be good and let God handle the enemy. Your interpretation has Paul advising them to be good to their enemy so their enemy will suffer. That's disturbing. I think you mistake Paul for Poe (as in Edgar Allan). Verse 14 says "Bless those who persecute you; bless and do not curse." But you insist that Paul turns around 180 degrees and tells us to do 'good' so as to bring a curse on the enemy's head.
And He most certainly will -- by "heaping holes of fire on their heads."
Sounds like a curse alright.
Frankly, I don't think I've ever heard a verse so misunderstood as your take on this one.
Should I be surprised?
Of course I guess if you insist on thinking God loves everyone, then floods, pestilence, disease and destruction are all divine love tokens, too, and not a result of God's wrath.
Yes and no, but another subject for another day.
Remind me never to tell you I'm feeling a little chilly. 8~)
Apparently, if I were still a member of the PCA, your fears might be justified. :P
As explained by the verse in context, "coals of fire" further distinguishes God's children from those not numbered among His family, those who are enemies of His children and thus, enemies of Him.
As 1000silverlings wrote: "Indeed, the Greek for "burning coals" is our English word anthrax, so might be whence comes our saying "a pox upon him",lol. At any rate I think the burning coals are meant to represent God's wrath."
Amen.
But, hey, if you want to think tossing burning coals of fire on someone's head is an act of kindness in order to keep them warm and toasty, that's your campfire prerogative.
“Your interpretation has Paul advising them to be good to their enemy so their enemy will suffer. That’s disturbing.”
Jesus said: “Ye have heard that it hath been said, Thou shalt love thy neighbour, and hate thine enemy. But I say unto you, Love your enemies, bless them that curse you, do good to them that hate you, and pray for them which despitefully use you, and persecute you” (Matt. 5:43–44).
Jesus is saying the best way to destroy an enemy is to befriend him, make him a brother. The Paul gives this instruction: “Therefore if thine enemy hunger, feed him; if he thirst, give him drink: for in so doing thou shalt heap coals of fire on his head” (Rom. 12:20). So, the best way to get rid of an enemy is to make him your friend, your brother.
This is why Jesus added: “But I say unto you, Love your enemies, bless them that curse you, do good to them that hate you, and pray for them which despitefully use you, and persecute you; That ye may be the children of your Father which is in heaven: for he maketh his sun to rise on the evil and on the good, and sendeth rain on the just and on the unjust. For if ye love them which love you, what reward have ye? do not even the publicans the same?” (Matt. 5:44–46).
Paul’s “coals of fire” are shame, that causes an enemy to burn as David states: Psa 83:14 “As the fire burneth a wood, and as the flame setteth the mountains on fire; So persecute them with thy tempest, and make them afraid with thy storm. Fill their faces with shame; that they may seek thy name, O LORD.”
In the seeking the Lord because of the shame caused by meeting their needs, they can become brothers in the Lord. It is not a sentimental emotion of love, it is Elisha leading the blind Syrian Army into the presence of the king where they could be killed and instead feeding them and sending them home well and they become friends and don’t invade again until the deed is forgotten. 2 Kings 6:13-22.
Shame, is a tool, it is leaving it to the Lord to do His will, but it is a product of recognizing evil in the presence of good deeds.